Bow stick and method of manufacture thereof



April 29, 1969 R. WURLITZER 3,440,918

BOW STICK AND METHOD OF MANUFACTURE THEREOF Filed Nov. 15, 1964 ill US. Cl. 84282 United States Patent 3,440,918 BOW STICK AND METHOD OF MANUFACTURE THEREOF Rembert Wurlitzer, deceased, late of New York, N.Y., by Anna Lee Wurlitzer, executrix, New York, N.Y., assignor to Rembert Wurlitzer, Inc., a corporation of New York Filed Nov. 13, 1964, Ser. No. 411,159

Int. Cl. Gd 3/16 2 Claims ABSTRACT OF THE DISCLOSURE A violin bow comprising a hollow stick made of hardened, plastic-impregnated Fiberglas 019th having 8 to 10 times as many fibers running substantially longitudinally as circumferentially and formed out of a trapezoidal piece of Fiberglas cloth wound on a conical mandrel so that the centerfiber of the trapezoid is substantially parallel to one of the generatoisof the conical surface of the mandrel, the tapered end of the stick having a conical internal taper that fits over a matching conical external taper of the head of the bow, the tapered part of the head having an internal cylindrical bore substantially matching the inner diameter of the immediately adjacent portion of the stick. I

This invention relates to the manufacture of violin bow sticks and the like and to the sticks themselves.

Setting aside the skill of the musician, the quality of tone to be derived from a violin or other musical instrument played with a bow is determined not only by the instrument, but by the bow as well. The bow is composed of several components, the principal ones of which are a long, slender stick having a lead at one end and a handle at the other, and the hairs, or fibers, strung from the head to the handle. While it is the drawing of the hairs across the strings of the instrument that produces the music, the stick is an important part of the acoustical system and must be very carefully selected so that it will not warp and so that it has the proper balance, which includes the proper taper as well as proper weight and distribution of the weight. It is also important that the stick not introduce any undesired resonances in the vibrating system.

It is an object of the present invention to produce a bow stick of high quality and acceptability. Other objects are 'to produce bow sticks in production quantities with good uniformity and at a price commensurate with the quality obtained.

These objects have been achieved by the production of a stick made of Fiberglas, according to a novel process. The Fiberglas is in the form of woven cloth having more threads per square inch in one direction than in the perpendicular direction. A piece of this cloth is wrapped around a mandrel so that the more densely packed fibers extend substantially length-wise and the other fibers extend more or less around the mandrel to produce a stick having the desired acoustical characteristics and the desired feel. Normally, the mandrel is in the form of a long, conical, very smooth rod and, accordance with this invention, the best stick is produced by cutting the Fiberglas into a trapezoidal shape with the more numerous, or more densely packed, fibers running perpendicular to the two parallel sides, and with the other fibers running across from one of the sloping sides of the trapezoid to the other.

The winding of the cloth on the tapered mandrel starts with the mandrel parallel to one of the sloping edges and proceeds preferably an integral number of turns so that the other sloping edge is directly over the other slop- 3,440,918 Patented Apr. 29, 1969 "ice ing edge when the winding of the cloth is finished. This requires that both the long and short parallel sides have a predetremined length approximately equal to an integral multiple of the circumference of the sections of the mandrel at which the long and short sides will be located. After the winding, the cloth is impregnated with a binder which is then hardened to produce a rigid stick, the stick is thereafter removed from the mandrel and attached to the other parts to make up a complete bow.

The invention will be described more fully and additional objects will be disclosed in the following specification, together with the drawings in which:

FIG. 1 shows a piece of cloth laid out for forming a conical bow stick and a tapered mandrel on which the cloth is to be wound;

FIG. 2 shows the head section of a bow;

FIG. 3 shows a fragment of the head in FIG. 2; and

FIG. 4 shows the end of the stick of FIG. 2.

FIG. 1 shows a piece of Fiberglas cloth '11 in the form of a trapezoid and a tapered mandrel 12 on which the cloth 11 is to be wound to form a stick. The mandrel is shown lying adjacent to one of the slanting sides of the trapezoidal Fiberglas cloth in the position that it would occupy at the start of the winding procedure. The shape of the cloth and the dimensions are carefully selected to produce a stick of exactly the proper dimensions and without any residual twist whatsoever. For this purpose, it has been found that Fiberglas having approximately 8 to 10 longitudinal fibers in one direction for each cross fiber should be used. The longitudinal fibers are indicated by reference character 13- and they run perpendicularly between the two parallel sides 14 and .16 of the trapezoid. The other fibers 17 are perpendicular to the fibers 13 and run between the two slanting sides 18 and 19.

The angles made by the sides 18 and 19 with the side 16 are carefully determined, as are the lengths of the sides 14 and 16, to produce as nearly as possible a precise fit when the cloth is wrapped around the mandrel 12. That is, if a single layer were to be wrapped around the mandrel 12, the length of the side 14 would be as nearly as possible equal to the circumference of a predetermined section of the mandrel 12 near the smaller end thereof, while the length of the side 16 would be as nearly as possible equal to a circumference of a given point near the larger end of the mandrel. In normal practice, however, more than one layer is wound around the mandrel, and thus the length of the side :14 should be an integral multiple of the circumference of a particular point near the smaller end of the mandrel 12, taking into account the additional length of cloth required to complete each layer over the preceding layer. Similarly, the length of the side 16 must be the same number multiple of the circumference of a predetermined section of the mandrel 12 near the larger end thereof, again taking into account the additional length that will be required for each additional layer wound upon the mandrel. The result is a winding in which the beginning edge 18 runs along a generator of the mandrel 12 and the finishing edge 19 also runs along substantially the same generator of the mandrel.

As may be seen, neither the threads 13 nor 17 are parallel to the generator of the mandrel 21 at the beginning edge 18. However, as may be envisioned, the angle between the threads 13 and a generator of the mandrel 12 at the beginning edge will be substantially equal in magnitude but opposite in direction to the angle between the threads 13 and a generator of the mandrel at the finishing edge .19. This is the same as saying that the threads 13 will be skewed with respect to the mandrel at the beginning edge 18 and will be skewed equally and at the opposite direction at the finishing edge :19. In the center of the cloth 11, as shown in dotted lines,

a generator of the mandrel 12 is substantially coincident with the central one of the thread 1 3. As a result, there will be a substantially equal number of threads 13 skewed in opposite directions on both sides of the center one of the threads and there will, therefore, be no residual twist produced by the Fiberglas cloth 11.

After the cloth 11 has been completely wound on the mandrel 12, it may be impregnated with any suitable impregnant and hardened or permitted to harden into a rigid structure. Thereafter the mandrel 12 is removed so as to leave a hollow, tapered, Fiberglas stick.

After the stick itself has been formed, it must be attached to the remaining parts of the bow in order to form a complete bow. FIG. .2 shows a head 21 to which the sound-producing fibers 22 are attached. It is essential to maintain substantially the same resonances and elasticity in the synthetically produced bow, according to the present invention, as in bows made of natural wood. Although the head' 21 may be cast of synthetic material, care must betaken to assure that it does not stiifen the bow too much'at the point where it joins the stick .111. Therefore, instead of forming a butt joint between the end of the stick 111 and the head 21, the two are mutually oppositely tapered to provide a long area of contact.

FIG. 3 shows a cross-sectional view of a fragment of the head '21 and illustrates the tapered end 23 thereof joining it to the stick 111. As a further measure to reduce stiffness, the neck portion 23 may be bored out so as to be hollow.

FIG. 4 shows the end of the stick that fits over the neck portion 23 of the head 21. As may be seen, the end of the stick is reamed out along a taper corresponding to the taper of the neck 23. Moreover, the diameter of the inner bore 24 of the stick 111 is substantially equal to the diameter of the bore in the neck 23 so that there will be no sharp line of demarcation between the stick material 111 and the head material 21 that would form acoustically-loaded points which might produce adverse resonances in the bow that would be transmitted to the violin, viola, or the like.

While this invention has been described in terms of a specific embodiment, it will be understood by those skilled in the art that modifications may be made therein with- 4 out departing from the true scope of the invention, as determined by the following claims.

What is claimed is:

.1. A violin bow comprising: a head and hollow frustoconical Fiberglas stick comprising a plurality of layers of Fiberglas, said'stick having a conical bore, said Fiberglas having longitudinal fibers extending substantially lengthwise of said stick and other fibers substantially perpendicular thereto, said lengthwise fibers being approximately 8 to 10 times as numerous per square inch as said fibers substantially perpendicular thereto and the center fiber of said lengthwise fibers in the center layer being substantially parallel to one of the generators of said conical bore, said stick having a reverse conical bore at the smaller end thereof and said head having a neck with a conical external surface substantially matching said reverse conical bore and extending therein and cemented thereto. and said neck having a substantially cylindrical bore with a diameter substantially equal to the smallest diameter of the tapered end-of said neck and substantially equal to the diameter of the portion of the bore in said stick at the confluence of said conical bore and said reverse bore.

2. The bow of claim .1 in which the length of said bore in said head is at least substantially as great as the length of that portion of said stick overlapping said head.

References Cited UNITED STATES PATENTS 1,912,961 6/1933 Allison 84282 2,252,929 8/1941 Heddon 84282 2,571,717 10/1 951 Howald et a1. 43-18 2,726,185 12/1955 Howald 156-174 2,749,643 6/1956 Scott 43-17 3,313,541 4/1967 Benkoczy et al 156-192 2,637,674 5/1953 Stahl 156-194 2,768,921 10/1956 Pigg 156-194 2,624,225 1/1953 Nebel 84282 2,730,001 1/1956 Martin 84282 RICHARD B. WILKINSON, Primary Examiner.

LAWRENCE R. FRANKLIN, Assistant Examiner. 

